### Conveners

#### Vacuum Structure and Confinement

- Nigel David Cundy (Seoul National University)

#### Vacuum Structure and Confinement

- Cosmai Leonardo

Dr
Claudio Bonati
(Università di Pisa)

7/29/16, 2:00 PM

Vacuum Structure and Confinement

Talk

Studies of the large N behaviour of the topological properties of gauge theories typically focused on the large N scaling of the topological susceptibility. A much more difficult task is the study of the behaviour of higher cumulants of the topological charge in the large N limit, which up to now remained elusive. We will present first results confirming the expected large N scaling of the...

Miguel Francisco Garcia Vera
(NIC, DESY & Humboldt Universitat zu Berlin)

7/29/16, 2:20 PM

Vacuum Structure and Confinement

Talk

We present a precise computation of the topological susceptibility $\chi$ of SU($N$) Yang–Mills theory in the large-$N$ limit. The computation is done on the lattice, using high-statistics Monte Carlo simulations of the SU($N$) Yang-Mills theories, with $N=3, 4, 5, 6$ and three different lattice spacings. Two major improvements allowed us to go to finer lattice spacing and larger $N$ compared...

Mr
Vadacchino Davide
(Universita' degli Studi di Torino - INFN Torino)

7/29/16, 2:40 PM

Vacuum Structure and Confinement

Talk

The dual formulation of the compact U(1) lattice gauge theory in three spacetime dimensions allows to finely study the squared width and the profile of the confining fluxtube on a wide range of physical interquark distances. The results obtained in Montecarlo simulations are compared with the predictions of the effective bosonic-string model and with the dual superconductor model. While the...

Dr
Andrea Rucci
(University of Pisa and INFN Pisa)

7/29/16, 3:00 PM

Vacuum Structure and Confinement

Talk

I will discuss some recent results obtained in the study of the strong quark-antiquark
interaction in the presence of intense external magnetic fields. At zero temperature
the external field induces anisotropies in the static quark potential, that affect both
the spectrum and the decays of the heavy mesons. In the quark-gluon plasma phase
the screening masses do not show significant...

Dr
Michael Teper
(University of Oxford)

7/29/16, 3:20 PM

Vacuum Structure and Confinement

Talk

We summarise the most striking features of the spectra of closed
confining flux tubes, for the flux in the fundamental
and some other representations. We compare to recent theoretical
predictions. In $D=2+1$ we present results for the continuum string
tensions for theories ranging from SU(2) to SU(16) and we determine
the leading correction to the N-dependence of k-strings.

Dr
Leonardo Cosmai
(INFN)

7/29/16, 3:40 PM

Vacuum Structure and Confinement

Talk

We investigate the transverse profile of the chromoelectric field
generated by a quark-antiquark pair in the vacuum of (2+1) flavor QCD.
Monte Carlo simulations are performed adopting the HISQ/tree action
discretization, as implemented in the publicly available MILC code,
suitably modified to measure the chromoelectric field.
We work on the line of constant physics, with physical...

Dr
Waseem Kamleh
(University of Adelaide)

7/29/16, 4:30 PM

Vacuum Structure and Confinement

Talk

We reveal a fundamental connection between centre
vortices and several key features associated with dynamical
chiral symmetry breaking and quark confinement. Calculations are
performed in pure $\mathrm{SU}(3)$ gauge theory using the chiral
overlap fermion action. Starting from the original gauge field, a
vortex identification procedure yields vortex-removed and vortex-only
backgrounds....

Dr
Nigel David Cundy
(Seoul National University)

7/29/16, 4:50 PM

Vacuum Structure and Confinement

Talk

In earlier work, we used a gauge independent Abelian Decomposition to show that Abelian degrees of freedom where wholly responsible for the static quark postential. The Abelian decomposition contains a Maxwell part and Topological part, whose contribution to the string tension can be analysed theoretically and numerically, and arises because of the existence of a certain type of monopole. If...

Akihiro Shibata
(Computing Research Center, KEK)

7/29/16, 5:10 PM

Vacuum Structure and Confinement

Talk

The dual superconductivity is a promising mechanism for quark confinement. We have presented a new formulation of the Yang-Mills theory on the lattice, that enables us to change the original non-Abelian gauge field into the new field variables such that one of them called the restricted field gives the dominant contribution to quark confinement in the gauge-independent way. We...

28.
The Dark Side of the Propagators: analytical approach to QCD in the infrared of Minkowski space.

Prof.
Fabio SIRINGO
(Dipartimento di Fisica e Astronomia, Università di Catania)

7/29/16, 5:30 PM

Vacuum Structure and Confinement

Talk

Since most of the non-perturbative approaches to QCD rely on numerical calculations in the *Euclidean* space, many important dynamical information cannot be easily extracted because of the ill-defined problem of analytic continuation for a limited set of data points.
On the other hand, by a shift of the expansion point, a perturbative approach has been developed[1,2] that has the nice feature...

Dr
Andre Sternbeck
(University of Jena)

7/29/16, 5:50 PM

Vacuum Structure and Confinement

Talk

We report on new results for the triple-gluon and the quark-gluon vertex in Landau gauge. Our results are based on two-flavor and quenched lattice QCD calculations for different quark masses, lattice spacings and
volumes. We will focus on the momentum dependence of the different tensor structures.

Dr
Paulo Silva
(Center for Physics, University of Coimbra)

7/29/16, 6:10 PM

Vacuum Structure and Confinement

Talk

In lattice QCD the computation of one-particle irreducible (1PI) Green's functions with a large number (> 2) of legs is a challenging task. Besides tuning the lattice spacing and volume to reduce finite size effects, the problems associated with the estimation of higher order moments via Monte Carlo methods and the extraction of 1PI from complete Green's functions are limitations of the...